[Association between long-term blood pressure change and the incidence of cardiovascular diseases: a population-based cohort study].

To explore the association between long-term changes in blood pressure (BP) levels and the incidence of cardiovascular diseases (CVD). A total of 5 752 participants, who participated baseline examination in 1992-1993 and re-examination in 2007, were followed up till December 31, 2013 according to the study protocol of the Chinese Multi-provincial Cohort Study. Participants were stratified by baseline BP and re-examination BP and cross-combined into 9 subgroups. The 20-year incidence of acute cardiovascular events, acute coronary heart disease (CHD) and acute stroke events were analyzed and association between disease incidence and 15-year changes in BP were determined using the competing risk regression model. (1) There were 523 CVD events (170 CHD, 373 stroke) during the 20 years follow up. The number of participants with baseline systolic blood pressure (SBP)/diastolic blood pressure (DBP) of <130/80 mmHg (1 mmHg=0.133 kPa), 130-139/80-89 mmHg, and hypertension were 2 892 (50.3%), 1 328 (23.1%) and 1 532 (26.6%), respectively. (2) Among participants with baseline SBP of 130-139 mmHg or DBP of 80-89 mmHg, 870 (65.5%) progressed to hypertension and 279 (21.0%) maintained at the same stratum over a 15-year follow up period. (3) After adjustment for age, sex, body mass index, smoking status, diabetes, total cholesterol, and high-density lipoprotein cholesterol at baseline, participants maintained SBP/DBP at 130-139/80-89 mmHg had a higher risk of developing acute cardiovascular events, CHD and stroke with the hazard ratios () and 95% confidence interval (95) of 2.04 (1.16, 3.57), 3.29 (1.30, 8.35) and 1.63 (0.80, 3.33), compared with those who maintained their SBP < 130 mmHg and DBP <80 mmHg. Participants whose BP increased from 130-139/80-89 mmHg to hypertension over the follow up period had 2.81-fold (1.84, 4.29), 3.17-fold (1.43, 7.03) and 2.71-fold (1.65, 4.44) higher risk for the incidence of acute cardiovascular events, CHD, and stroke, respectively, compared with participants who maintained their SBP <130 mmHg and DBP <80 mmHg. Participants with SBP/DBP of 130-139/80-89 mmHg have a high long-term risk for progression to hypertension. Sustained exposure to SBP/DBP of 130-139/80-89 mmHg or higher increases the risk of CVD incidence, and our results highlight the importance of early prevention for participants with this BP stratum.